Waste heat boiler casing structure of corrugated plates



H. BASTEK Dec. 8, 1959 WASTE HEAT BOILER CASING STRUCTURE OF CORRUGATED PLATES 2 Sheets-Sheet 1 Filed Aug. 3. 1954 INVENTOR HEMP/(H 34: 75K 2 ATTORNEY United States Patent- 2,916,021 WASTE HEAT BOILER CASING "STRUCTURE OF CORRUGATED PLATES Heinrich Bastek, Mulheim-Ruhr, Germany, ass'ignor to The Babcock 8; Wilcox Company, New York, N.Y., a corporation of NewJersey Application August 3, 1954, Serial 'No. 44.7,=5-13 Claims priority, application Germany August 8, 1953 6 Claims. ((31. '122494) The present invention relates to a .structure for enclosing .aheating gas flow passageway, and more particularly relates to an enclosure of substantially rectangular crosssection for enclosing and supporting a vapor generator.

Heretofore, the metallic casing .or enclosure fora waste heat vapor generator has customarily been supported either from the structural supports of the vapor generator, the elements of the vapor generator or from separate structural elements. Occasionally the casing of a waste heat boiler has been constructed to be self-supporting and to also form a support for the pressure parts of the boiler. In these circumstances, the casing has been constructed of circular cross-section so as to provide the necessary structural strength and rigidity. A casing of cylindrical cross-section, however, requires a special arrangement of the tubular heat exchange elements of the boiler, i;e., the tubular elements must be coiled to fit the circular crosssection so as to avoid by-passing of heating gas around the heating surfaces. Alternately, with .a circular casing, guide walls may be constructed within-the casing to direct the flow of heating gases across the heating surfaces. The use of guide walls drastically reduces the crosssectional flow area of the casing, and is .uneconomi'cal in cost.

According to the invention, the casing or enclosure is constructed from a plurality of corrugated metal sheets or plates to form a gas flow passageway .of :polygonal or generally rectangular cross-section. ,Advantageously, the

corrugated plates may be of readily available commercial sizes and weights. Corrugated iron plates have sufficient stiffness both perpendicular and parallel to the corrugations to avoid or minimize the use of flat or angle iron stiffeners such as would be required with flat plate of the same thickness. Only the edges of the corrugated iron plates are stiffened by .flat or angle iron members :to form flanges for attachment to adjoining sections which are constructed in the same manner. The corner edges of each section are shaped to form an outwardly projecting angle with the adjoining edges of the corrugated sheets or plates welded together so thateach section of the casing forms a box which has a structural strength considerably greater than would be attained with :the same weight of metal using flat plates.

The various features of novelty which characterize my invention are pointed out with particularity .in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

Of the drawings:

Fig. l is an elevation, .partly 'in section, of the casing or enclosure of the present invention as applied to the installation of a waste heat boiler;

Fig. 2 is an elevation, partly in section, taken at 90 of Fig. 1;

Figs. 3 and 4 are enlarged views .of a portion of the side walls (with the insulation removed) shown in Figs. 1 and 2, respectively;

Fig. 5 is a partial horizontal section taken on 5-5 of Fig. 4; and

2,916,021 Patented Dec. 8, 1959 Fig. .6 is a plan of the base section shown in Fig. 4.

While the illustrated embodiment of the enclosure or casing of the invention is shown as applied to .a waste heat boiler it will be understood that the invention can be readily applied for other types of service. It will also be understood that the axis of the corrugations in the casing can be oriented as shown in the drawings, or the axis of the corrugations can be at right angles to the direction of gas flow through the enclosure. In the latter arrangement the longitudinal strength of the assembly will be less than the transverse strength.

As shown in the drawings, the waste heat boiler is yertically arranged within the casing of the present invention, with the casing defining an upwardly extending gas flow passageway of substantially uniform flow area throughout 'its vertical extent. Waste heat -flue gases enter the unit through an inlet duct 1 formed 9111 the foundation of the waste heat boiler unit and discharged to the atmosphere through an exhaust fan 2 positioned on the top of the boiler.

The casing enclosing the waste heat boiler is made up of a plurality of sections 311, inclusive, with the bottom section 3 mounted upon a base frame 12 supported on the foundation. The top section 11 is provided with a structural framework 13 on the upper end thereof to support the exhaust fan 2.

The sections 3-11, inclusive, are each constructed of four sheets of corrugated plates 22 .and 23 of commercial size and weight with the edges of each sheet bent parallel to the corrugations to form an outwardly protruding corner 24 (see Fig. 5). The edges of adjoining plates are welded together throughout the length thereof to 'form a gastight joint therebetween With the construction described each section is generally rectangular in crosssection.

Each section of the casing is provided with :a set of plates 19 on the lower edge, :and angle irons 2.0 on the upper edge, to form flanges for the attachment .of :adjoining sections. The flanges so formed stiffen the section, and when the flanges of adjoining sectionszare com-. bined an airtight joint is formed. In the illustrated .embodiment of the invention the leg 21 :(see Figs. 3, 4 and 5) of the angle iron flange is utilized for the attachment of insulating material 25 to the casing. As shown particularly in Figs. 3 and 5, the flanges formed by the plates 19 and the angles 20 cover the ends of the corrugated plates 22 and 23 and extend outwardly of the plates so that the insulation25 is spaced outwardly of the metal casing. The sections .341, inclusive, can be connected by welding without the use of the flanges formed by the plates 19 and angles 20, but in the usual installation the use of the flanges will be advantageous in stiffening :the assembly.

The waste heat boiler casing is provided with openings 14 in one wall thereof for the insertion of the tubular heat exchange elements 28-31, inclusive. The openings 14 are bounded by flanges 18, which may be angle "irons as shown in Figs. 4 and '5, or may the constructed from bars or plates. Panels of corrugated plate havingan exterior frame of plates or angles'fit against the flanges 1 8 to form -,a closure for the openings 14. The panels are removably attached to the framework of the-openings 14 to provide an airtight joint therewith, and are removable from the casing for access to the tubular heat exchange elements 28, 29, .30z1and 3J1. Openings '15 in the wall of the casing permit the assembly and maintenance of :soot blowers positioned in the gas pass of the unit. These openings are also provided with a peripheral flange, and panel inserts are removably secured in the opening 15 for closure purposes.

.As shown, .particularly inFigs. 2 and 3, the tubular heat exchange elements which may include vapor gencrating and superheating units 28, 29 and 30, and economizer units 31 are pendently supported from the casing by transv ersely extending beams 16. The beams 16 may be of channel cross-section, as shown, or of other desirable Section. Theends of the-beams extend through thecorrugated plate sections and rest on the flanges 19 and 20 connecting adjoining sections of the casing. The ends of the beams 16 are housed in boxes 17 formed of plate which is Welded to the corrugated plates of the casing and provided with a closure plate 32. The plate 32 is cut to the contour of the beam cross-section and welded to'the beam substantially flush with the casing surface after the beams 16 and the tubular heat exchange elements are assembled in the casing.

Boiler pressure parts which are positioned out of the gas flow path, such as the drum 27, may be supported from the casing by a bracket 26, or the like. Conduit means, as shown in Figure 1, connects at least one of the units of the heat exchange elements and said drum for flow of fluid therebetween. When the parts are unusual 1y heavy external parts are usually supported by a structure framework separate from the boiler casing, but tied thereto for coordinate movement during expansion and contraction of the casing and heat exchange elem'ents.

While in accordance with the provisions of the statutes 1 have illustrated and described herein a preferred embodiment of the invention, those skilled in the art will understand that changes may be made in the method of operation and form of'the apparatus disclosed without departing from the spirit of the invention covered by my claims, and that certain features of the invention may sometimes be used to advantage without a corresponding use of other features.

What is claimed is:

1. A casing for a Waste heat boiler comprising a plurality of cormgatedplate sections, each section including corrugated plates joined in gastight relationship along opposite edges to an adjoining corrugated plate, flange means for connecting adjoining sections in gastight relationship, a plurality of heat exchange elements positioned in vertically spaced units with each unit pendently supported from separate vertically spaced flange means of said corrugated plate sections, a vapor receiving drum positioned on theexterior of said casing, conduit means connecting at least one of the units of said heat exchange elements and said drum for flow of fluid therebetween, and means for passing hot gases through said casing in contact with said heat exchange element.

2. A self-supporting enclosure for confining a flow of hot' gases according to claim 1 wherein said corrugated plates are positioned with the axis of corrugation parallel to the directionof gas flow.

3. A casing for a Waste heat boiler comprising a plurality of corrugated plate sections, each section including corrugated plates joined in gastight relationship along opposite edges to an adjoining corrugated plate and defininga gas flow passageway substantially rectangular in cross-section, flange means for joining adjoining sections in gastight relationship, tubular heat exchange elements positioned within said casing in vertically spaced units, structural members arranged to pendentlysupport each unit of said heat exchange elements at a plurality of verticallyspaced positions on the flange means of said cas ing, an'dmeans for passing heating gases through said corrugated plate casing and in contact with said heat exchange elements. I V

4. A casing for a waste heat boiler comprising a plurality of corrugated plate sections, each section including corrugated plates joined in gastight relationship along opposite edges to anadjoining corrugated plate and defining a gas flow passageway of polygonal cross-section, plate means attached to an edge of each of said corrugated plates and defining alfla'nge on one end of each section disposed generally normal to the direction of gas 4 flow,"angle iron means attached to-an edge of each ofsaid corrugated plates and defining a flange on another end of each section disposed generally normal to the direction of gas flow, said sectionsjoined by attaching the plate flange of one section to the angle iron flange of an adjoining section, tubular heat exchange elements positioned said casing in vertically spaced units, structural members arranged to pendently support each unit of said heat exchange elements at a plurality of vertical- 1y spaced positions on the flange means of said casing, and means for passing hot gases through said casing and in contact with said heat exchange surfaces.

end of each section disposed generally normal to the direction of gas flow, said sections joined by attaching the plate flange of one section to the angle iron flange of an adjoining section, tubular heat exchange elements positioned within said casing in vertically spaced units,

T structural members arranged to pendently support each unit of said heat exchange elements at a plurality of vertically spaced positions on the flange means of said casing including beams extending transversely across said casing at positions spaced in the direction of gas flow 1 through said casing and with the opposite ends of said beams bearing upon said section flanges, and means for passing hot gases through said casing and in contact with said heat exchange surfaces.

6. A casing for a waste heat boiler comprising a plurality of corrugated plate sections, each section including corrugated plates joined in gastight relationship along opposite edges to an adjoining corrugated plate and defining a gas flow passageway of polygonal cross-section, plate means attached to an edge of each of said corrugated plates and defining a flange on one end of each section disposed generally normal to the direction of gas flow, angle iron means attached to an edge of each of said corrugated plates and defining a flange on another end of each section disposed generally normal to the direction of gas flow, said sections joined by attaching the plate flange of one section to the angle iron flange of an adjoining section, tubular heat exchange elements positioned Within said casing in vertically spaced units, structural members arranged to pendently support each unit of said heat exchange elements at a plurality of vertically spaced positions on the flange means of said casing including beams extending transversely across said'casing at positions spaced in the direction of gas flow through said casing and with the opposite ends of said beams bearing upon said section flanges, heat insulating means attached to and supported by the flange edge of said angle iron, and means for passing hot gases through said casing andin contact with said heat exchange elements.

References Cited in the file of this patent UNITED STATES PATENTS mm, an ab 

